UTC literally stands for Universal Time Coordinated (though it is typically
referred to as Coordinated Universal Time) and is the standard time common
to every place in the world. It is also known as Greenwich Mean Time
(GMT) and Zulu (Z). UTC is defined as the time at longitude 0 degrees,
the prime meridian. This is the longitudinal line that separates
the Eastern and Western Hemispheres, and happens to pass through the Greenwich
Observatory outside of London, England. All of our forecast products
and the computer models that provide us guidance are based on this universal
time zone.

When you see 12 UTC or 1200 UTC or 12Z (all are the same and depend
on forecaster preference), it refers to noon at Greenwich. 00 UTC
or 00Z is midnight Greenwich time. Translating this to your time
zone depends on where you live. Below is a table that provides some
UTC times and their conversion to the four time zones over the lower
48 for standard time.

STANDARD TIME

PACIFIC

MOUNTAIN

CENTRAL

EASTERN

0000Z/UTC

4:00 PM

5:00 PM

6:00 PM

7:00 PM

0300

7:00 PM

8:00 PM

9:00 PM

10:00 PM

0600

10:00 PM

11:00 PM

Midnight

1:00 AM

0900

1:00 AM

2:00 AM

3:00 AM

4:00 AM

1200

4:00 AM

5:00 AM

6:00 AM

7:00 AM

1500

7:00 AM

8:00 AM

9:00 AM

10:00 AM

1800

10:00 AM

11:00 AM

Noon

1:00 PM

2100

1:00 PM

2:00 PM

3:00 PM

4:00 PM

So, for example, if we write 12Z Friday, itíll be 7:00 a.m. Eastern
Standard Time (EST) and 4:00 a.m. Pacific. If itís 00Z Friday, it will
be 7:00 p.m. Thursday EST and 4:00 p.m. Thursday Pacific.

The table below is for daylight time.

DAYLIGHT TIME

PACIFIC

MOUNTAIN

CENTRAL

EASTERN

0000Z/UTC

5:00 PM

6:00 PM

7:00 PM

8:00 PM

0300

8:00 PM

9:00 PM

10:00 PM

11:00 PM

0600

11:00 PM

Midnight

1:00 AM

2:00 AM

0900

2:00 AM

3:00 AM

4:00 AM

5:00 AM

1200

5:00 AM

6:00 AM

7:00 AM

8:00 AM

1500

8:00 AM

9:00 AM

10:00 AM

11:00 AM

1800

11:00 AM

Noon

1:00 PM

2:00 PM

2100

2:00 PM

3:00 PM

4:00 PM

5:00 PM

Where can I find forecasts beyond 7 days?

The Climate Prediction Center
(CPC) is the branch of NOAA's National Weather Service (NWS) responsible
for issuing forecasts beyond 7 days. Their Outlooks
page provides links to each of their forecast products, including the 6-10
day and 8-14 day forecasts, along with monthly and seasonal forecasts.
Seasonal forecasts are produced in 3-month intervals and extend out to
over one year into the future. So, if you are looking for a forecast
for the upcoming winter (December-January-February) or summer (June-July-August),
simply click on the appropriate link. If you have any questions regarding
their forecasts, please click
here to e-mail them directly.

Where can I find historical or climatological weather data?

If you are looking for past weather information for a particular location,
you have a couple of options. The first is directly visiting the web site of NOAA's NWS
Weather Forecast Office (WFO) that serves the
desired location. You can access any of the local offices through
the NWS Home Page. If you
are not sure which is the correct WFO, type the city or town name in the
white box located in the upper left-hand part of their home page and click
GO.

If you are unable to find information from the local office, the National
Climatic Data Center has a very comprehensive collection of data and
will likely have whatever you need. You can access them through the
link above or call them at 828-271-4800.

How can I obtain past forecasts or analyses produced at the WPC?

Due to the large number of products issued and limited space, there
are only a few products residing on our site that are more than one day
old. They are:

How do I decipher the contractions/abbreviations used in your discussions?

We have a link on our site, Explanation
of Contractions, that provides definitions for most of the contractions
or abbreviations used in our discussions. Included in this list are
the two-letter state and territory abbreviations and contractions for the
numerical models our forecasters utilize.

How do I interpret the symbols and station model plots on your analysis
and forecast charts?

All of this information can be found by clicking on the links below.

Surface Fronts
describes the fronts depicted on our analysis and forecast maps, along
with how to interpret the 3-letter coding adjacent to the frontal boundary.

Precipitation
Areas explains the weather symbols and the difference between shaded
and unshaded precipitation areas used on our short range (1-2 day) forecasts.

Station Plots
provides interpretation of the station models depicted on our surface analysis
and observation charts.

For what time is the "today's forecast" on your home page valid?

The valid time for this product varies slightly depending on the weather feature
for which you are interested.

The general precipitation areas depicted are valid for a 12-hour
period during the current day, from 1200 UTC (7:00 a.m. EST) through 0000
UTC (7:00 p.m. EST).

Severe weather and flash flooding forecasts are valid for the 24-hour
period starting at 1200 UTC of the current day

Heavy snow and ice forecasts are usually valid from for the 12-hour
period during the current day (from 1200 UTC to 0000 UTC), however, if
warranted, may extend an additional 12 hours to 1200 UTC of the following
day.

Are the 5-day QPF and day 1, 2, and 3 QPFs based on the same guidance?

No. The 5-day QPF issued by our medium-range forecasters is based primarily on the 0000 UTC and
0600 UTC numerical model runs, with a quick glance at the 1200 UTC runs. The forecaster prepares a
forecast for days 4-5, then adds the days 1-3 QPF issued at about 1000 UTC to get a 5-day forecast.
All of this is based on 0000 and 0600 UTC model guidance. The forecaster then adjusts the 5-day
total based on quick looka the 1200 UTC model output.

What do the colors represent on your satellite images?

The infrared satellite imagery on our web site is "enhanced", which means that
the image is modified using a color scheme in order to bring out details in the cloud patterns.
The various colors are determined by the amount of energy, translated into temperature, that the
satellite is sensing. The image below represents the enhancement curve that is used in all
of the satellite imagery on our site. The numbers correspond to the temperature in degrees Celsius
that is associated with colors on the enhancement curve. The darker colors on the left side of the
represent warmer temperatures, while those to the right are colder. Since the
atmosphere cools with height, the areas in yellow, blue, red or green usually indicate progressively
higher (therefore colder) cloud tops. The shades of light gray show low cloud tops, while the dark
areas on the left side of the curve typically show that the skies are clear and the infrared imagery
is actually measuring the temperature of the land or ocean surface. However, infrared images can be
misleading in the winter under a very cold air mass. If the surface temperature is, for example, around -25
degrees Celsius (-13 degrees Fahrenheit, not unusual for December-February in the northern U.S. and Canada),
the dark yellow image will suggest cloud cover is present even if it is completely clear. In these
cases the image needs to be interpreted with caution.

Why has the domain for your surface analysis been reduced?

The previous, larger area (covering more of the Atlantic and Pacific Oceans) was defined at time when
the North American analysis was distributed by facsimile and only one chart could be sent for each analysis
time and this chart needed to meet the needs of a wide variety of users. Most users of NWS products were able
to receive only the WPC analysis and it needed to cover a wide area to meet the needs of all users.
NCEP now has three centers preparing surface analysis charts over much of the Northern Hemisphere and all are
available to all users. The oceanic areas eliminated from the WPC analysis are better
served by the Ocean Prediction Center (OPC) and the National Hurricane Center (NHC). Their later deadlines
allow more observational data to be incorporated into OPCs' and NHCs' analyses, resulting in a more accurate product.
Please see changes to the
North American surface analysis for more information.

Where can I get information about a career in meteorology?

Below are a few links that provide a good introduction into the field
of meteorology, including educational requirements and career opportunities.

A Career Guide
for the Atmospheric Sciences was published by the American Meteorology
Society (AMS) in 2000. This site provides a good overview of the
educational requirements (including links to colleges/universities that
offer degrees) and details the different career paths that exist in the
field of meteorology. This is probably the most comprehensive source
of information available.